The appearance of resistant phenotypes in cancer cells hinders the successful treatment of cancer. Members of the Structural Maintenance of Chromosomes (SMC) protein family have been shown to contribute to resistant phenotypes in cancer cells by enhancing DNA repair. The goal of this research project is to understand the biochemical funcfion of RecN, a bacterial SMC protein, in the DNA repair mechanism of the radio-resistant bacterium Deinococcus radiodurans (DEIRA). To accomplish this goal, two aims have been developed. Aim 1 will describe the biochemical properties of RecN by testing the hypothesis that RecN is a DNA binding, ATP hydrolyzing protein that requires these biochemical acfivifies to facilitate the assembly of DNA fragments. Aim 2 focuses on determining the role of RecN in the biochemical processes implicated in the DNA double-strand break repair mechanism of DEIRA by tesfing the hypothesis that RecN facilitates the repair of DNA double-strand breaks by bridging DNA molecules together. A combinafion of genefic and biochemical methodology will be used to test our working hypotheses. These techniques include a spectrophotometric enzyme assay to assess ATP hydrolysis acfivity of RecN as well as various DNA binding techniques to examine the acfivity of this protein. This project is relevant to public health because the information obtained can provide basic knowledge about a group of proteins associated with the development of resistance to cancer therapy by cancer cells. The informafion acquired in this study can be use to improve the efficacy of cancer therapy.